| 1982 – 2019 | Los Angeles County USC Medical Center, Los Angeles, United States |
| 1983 – 2019 | Keck School of Medicine of USC, Los Angeles, United States |
| 1988 – 2019 | University of Southern California, Los Angeles, United States |
| 2016 – 2019 | Los Angeles City & County CoC, Los Angeles, United States |
| 2011 | Departments of Pathology, Chicago, United States |
| 2010 | University of Peradeniya, United States |
| 1988 – 2006 | David Geffen School of Medicine at UCLA, Los Angeles, United States |
| 1997 – 2006 | USC Norris Comprehensive Cancer Center, Los Angeles, United States |
| 2002 | British Hospital Montevideo, Montevideo, Uruguay |
| 2000 | Cleveland Clinic Foundation, Cleveland, United States |
| 1996 | University of California, San Francisco, San Francisco, United States |
| 1989 – 1995 | Los Angeles County-University, Los Angeles, United States |
| 1993 | University at Buffalo, The State University of New York, Buffalo, United States |
| 1993 | Verdugo Hills Hospital, Glendale, United States |
| 1993 | University of Miami, Coral Gables, United States |
| 1992 | University of Colorado School of Medicine, Denver, United States |
| 1991 | USC School of Pharmacy, Los Angeles, United States |
| 1991 | Good Samaritan Hospital Los Angeles, Los Angeles, United States |
| 1991 | California Medical Association, Sacramento, United States |
| 1984 | Departments of Surgical Pathology, Los Angeles, United States |
| 1976 – 1980 | University of Colombo, Colombo, Sri Lanka |
| 1976 – 1980 | University of Colombo Faculty of Medicine, Colombo, Sri Lanka |
| 1975 | University Paediatric Unit, Colombo, Sri Lanka |
